Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Takeshi Maeda

Takao Nishida

Keita Ito

Yasuhiro Shimizu

Yasutake Ryu

Koji Kasai

Tomoki Fukushima

Yoshihisa Shinogi

Tadafumi Hirose

Hiroaki Kojima

Akihisa Shinoda

Naoya Toida

Kenji Higashi

Ryuji Tsuru

Tamotsu Momosaki

Yuji Shimada

Toshifumi Kochi

Shouhei Kasagi

Yasushi Shimazaki

A vertical-type air-cooled OHV engine includes a valve operating system and has a shroud guiding cooling air, which is generated by a cooling fan driven by a crankshaft such that the cooling air flows in an up-down direction with respect to a cylinder head. Intake and exhaust valves are arranged respectively on opposite sides of a vertical plane that is parallel to an axis of the crankshaft and that includes an axis of a cylinder bore. Accordingly, it is possible to provide a vertical-type air-cooled OHV engine capable of evenly cooling both of intake and exhaust valves without changing a route of cooling air.

Vertical-type air-cooled OHV engine

An oil level detection apparatus having a float-type oil level detector () and a mode switching unit. The oil level detector emits a signal indicating that the oil level has dropped when a movable contact disposed on a float () makes contact with fixed contacts once the level of oil (Lu) has dropped to a lower limit level. The mode switching unit switches between one of two modes selected from a first mode for actuating the alarm and stopping the engine () in accordance with the level drop signal, and a second mode for actuating the alarm and continuing to operate the engine () in accordance with the level drop signal.

Engine oil level detection system

An engine-driven generator is provided that is formed by supporting an engine () and a generator () on a frame (), wherein the frame () is formed as an open periphery framework type, within this frame () a duct member () is disposed around the outer periphery of the engine () and the generator (), the duct member () defining a series of cooling air passages () between itself and the engine () and generator (), a cooling fan () is provided in the cooling air passage (), the cooling fan () being driven by the engine (), an intake box () having an intake opening () at an outer end thereof and housing an electrical component () is connected to the upstream end of the duct member (), and an exhaust box () having an exhaust opening () at an outer end thereof and housing an exhaust muffler () of the engine () is connected to the other end of the duct member (). A compact engine-driven generator that enables running noise to be reduced can thereby be provided.

Engine-driven generator

In a handheld type four-cycle engine, a valve operation mechanism includes a camshaft rotatably supported in a cylinder head so as to open and close an intake valve and an exhaust valve and a timing transmission placed on one side outside an engine main body and providing association between a crankshaft and the camshaft, and a centrifugal clutch for power output is mounted on the crankshaft on the opposite side outside the engine main body. The timing transmission and the centrifugal clutch being positioned at the two ends of the crankshaft improves the weight balance, the centre of gravity of the engine can be made as close to the central part of the crankshaft as possible, which, together with the reduced weight, can enhance the operability of the engine.

Handheld type four-cycle engine

In a working engine including a bearing mounted on an outer wall of a crankcase for carrying a crankshaft, an oil seal mounted on the outer wall of a crankcase and disposed outside and adjacent the bearing, and a cooling fan which is attached to an outer end of the crankshaft adjacent the oil seal with its blades turned toward the crankcase and which has blades protruding toward the crankcase, a cylindrical protective tube is formed on an outer sidewall of the crankcase to cover ends of bosses of the cooling fan, and a foreign matter-beating piece is formed on the cooling fan in proximity to an outer peripheral surface of the protective tube. Thus, even if a long foreign matter drawn in by the cooling fan such as a weed and the like has been entangled around the crankshaft, it can be beaten and loosened, or cut by the foreign matter-beating piece rotated along with the cooling fan. Therefore, it is possible to prevent the entanglement around the foreign matter around the crankshaft, thereby avoiding damage to the oil seal as a result of the entanglement.

Foreign matter entanglement-preventing device in working engine

An engine head cover structure has a head cover joined to the upper end of a cylinder head so as to define a valve operation chamber therebetween. The head cover includes therein an oil recovery chamber to which oil resided in the valve operation chamber is recovered by suction and a breather chamber that removes blowby gas from the valve operation chamber being provided in the head cover. The breather chamber is defined between a partition plate mounted on an inner wall of the head cover via clips and a surface of the roof of the head cover, and the oil recovery chamber is defined between the partition plate and a partition body welded thereto. It is thus possible to form the oil recovery chamber and the breather chamber without splitting the roof of the head cover, thereby making inspection of the joint for oil tightness unnecessary.

Engine head cover structure

In a valve-operating mechanism in a 4-cycle engine, a timing transmitting device is disposed on one side of an engine body. A cam device includes a cam coupled to a driven pulley of the timing transmitting device on one side of a cylinder head, intake and exhaust rocker shafts rotatably carried in the cylinder head, intake and exhaust cam followers secured to one ends of the rocker shafts with their tip ends in sliding contact with the cam, and intake and exhaust rocker arms secured to the other ends of the intake and exhaust rocker shafts with their tip ends abutting against the intake and exhaust valves. Thus, the cam of the cam device can be disposed on one side of the cylinder head to effectively reduce the entire height of the engine.

Valve-operating mechanism in 4-cycle engine

In an engine valve operation mechanism, opposite ends of a support shaft that supports a cam in a rotatable manner are supported in a first support hole of a first support wall formed in a cylinder head and a second support hole of a second support wall placed inwardly from the first support wall relative to the cylinder head, thereby allowing the support shaft to be inserted into the first support hole and the second support hole from outside the cylinder head, and an inner face of a head cover prevents the support shaft from becoming detached from the first support hole. The axial movement of the cam support shaft can thereby be restricted without employing a special stopper member, and the leakage of lubricating oil for the support shaft can be prevented without using a special sealing member.

Engine valve operation mechanism

A breather device for an engine comprises a gas-liquid separation chamber communicating with the crankcase chamber through the one-way valve, a breather passage opening the gas-liquid separation chamber into an air cleaner, first and second oil suction holes arranged below and above an inner end of the breather passage opening to the gas-liquid separation chamber, and an oil passage communicating the first and second oil suction holes to an oil reservoir chamber having a pressure lower than that of the gas-liquid separation chamber. This construction enables the oil separated from the blow-by gas and liquefied in the gas-liquid separation chamber to be returned quickly to the oil reservoir chamber through the first or second oil suction holes, irrespective of whether the engine is in an normal upright position or an inverted position.

Breather device for engine

A decompression mechanism in an engine is provided, which is constructed so that a centrifugal weight, a pivot supporting the centrifugal weight on a driven timing gear, and an operating pin adapted to transmit the swinging movement of the centrifugal weight to a decompression cam shaft, can be formed as a single piece from a single steel wire, thereby providing a reduction in cost. The centrifugal weight is formed into a bow-like shape from a steel wire, and a pivot and a pin are formed by bending the steel wire sideways from opposite ends of the centrifugal weight.

Growing community of inventors

Wako, Japan

Takeshi Maeda