Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Yoshitaka Seki

Hiroshi Nakagome

Jun Hariu

Toshihisa Nagashii

Hitoshi Akaoka

Yoshiyuki Kurayoshi

Kiyoshi Katagiri

Hiromi Sumi

Takeshi Wakabayashi

Yoshitaka Hayama

Terunari Saiki

Takeru Abe

Megumu Okada

Toshimitsu Suzuki

Shunichi Nakajima

Akira Sonobata

Takashi Doi

Naoshi Iizuka

Shin Watanabe

Satoshi Hirayanagi

Kosei Hayashi

Kouichi Kobayashi

Masataka Nakano

Hiromi Shibata

Yasuki Ito

Koichi Ota

Naoyuki Saitou

An exhaust device includes left and right exhaust pipes and mufflers connected to a downstream side of the left and right exhaust pipes. The pair of left and right exhaust pipes respectively includes a merging portion. A catalyst is provided to the merging portion respectively. The pair of left and right exhaust pipes respectively includes, on a downstream side of the catalyst, a branching portion that has one side thereof extending to the muffler and the other side thereof extending to a connecting pipe. An oxygen sensor is provided to one side on a downstream side of the pair of left and right branching portions.

Exhaust device of motorcycle

A structure for sufficiently spacing a steering handle from a top bridge, thereby greatly improving design flexibility. A relief portion for allowing the deformation of a washer is formed to overlap a second contact surface and adjacent to a first contact surface as viewed in the axial direction of each bolt member. The first contact surface is located so as not to overlap the second contact surface as viewed in the axial direction of each bolt member. Therefore, a bending force acts on the washer to allow the deformation of the washer. That is, the washer can exhibit a spring function to relax the effect of the bending force. As a result, the steering handle can be sufficiently spaced from the top bridge to thereby greatly improve design flexibility.

Fastening device

An intake air passage, formed through a motorcycle body frame, reduces changes in pressure within an air routing duct member due to opening and closing of a throttle, and also reduces pipe resonance of the air routing duct member. The air routing duct member extends longitudinally from the intake air passage and directs fresh air to another air passage. The air routing duct member includes openings that communicate with hollow sections provided in a portion of an adjacent support structure, such as an instrumentation support member. When the throttle is opened rapidly, air from the hollow sections is temporarily supplied to the air routing duct member, reducing changes in internal air pressure in the air routing duct member due to throttle operation. Resonance chambers are formed above the air routing duct member, and communicate through communication pipes with a space within the air routing duct member to reduce duct pipe resonance.

Air routing structure for a motorcycle, and motorcycle including same

A mold and a die-cast manufacturing method for the die-cast product, in which a main frame which is contiguously formed with a head pipe constitutes a portion of a hollow light-weight-metal-made vehicle-body frame. The mold includes a core for forming an inner space of the hollow vehicle-body frame. The core includes a core body and a plurality of splints mounted on the core body, the splints having approximately elliptical cross-sectional shapes. The long axes direction of ellipses of the splints are set parallel to a mold split surface of the mold. As a result, measurement of the positional accuracy of the splints is facilitated, a clearance between the splint and the mold can decrease by increasing the dimensional accuracy of splint mounting portions of the mold based on sizes of the splints, and the frame can be manufactured with high dimensional accuracy.

Vehicle body frame, die-cast product, mold for die-cast product and die-cast method

To arrange a steering damper behind a head pipe in a compact manner while suppressing the influence of the steering damper on an intake duct which penetrates the vicinity of head pipes of a vehicle body frame. A steering damper is arranged between left and right main frames of a vehicle body frame and, at the same time, is arranged above or below an intake duct which penetrates the vicinity of a head pipe of the vehicle body frame.

Steering damper mounting structure

To easily secure a welding length when an opening is formed at a portion in the vicinity of a joint portion between a head pipe portion and a main frame portion. A front opening penetrating through a vehicle body frame across a head pipe portion and a main frame portion. A rib extending across the front opening along a front parting plane of the vehicle body frame. The rib being divided along the front parting plane and the edge portions of the divided rib portions opposing the outer periphery of the main frame portion are integrally joined.

Vehicle body frame structure

A cowling structure of a motorcycle having a radiator behind a front wheel, including a cowling which covers a periphery of the radiator from a front side of a handlebar, wherein an opening which extends in the longitudinal direction of the motorcycle is formed in the cowling such that the opening traverses an upper portion of the radiator in a side view, thus allowing air to pass through the opening and thus through the motorcycle in the lateral direction thereof.

Cowling structure of motorcycle

An intake duct structure having an intake path extending forwardly from a cleaner box, penetrating through an area near a head pipe of a vehicle body frame, and opening at a front end portion of a front cowl. During low speed operation of the engine, an intake valve closes a main intake path MR from a front end intake port and opens a sub-intake path SR from a lower portion intake port. On the other hand, during high speed operation of the engine, the intake valve opens the main intake path MR and closes the sub-intake path SR. The lower portion intake port opens forward of a head pipe inside a front cowl and obliquely downwardly toward the rear. With this arrangement, entry of rainwater into the intake path can be minimized during low speed operation of the engine.

Intake duct structure

A crankcase for a motorcycle is divided into an upper half and a lower half. A crankshaft, a main shaft, a counter shaft, and a pivot portion are arranged substantially on a straight line along a parting plane P of the crankcase. An eccentric cam and a pivot collar are disposed in the pivot portion, and a rear swing arm is connected to the pivot shaft. The upper half and lower half are vertically mated to each other in front of and behind the pivot portion and then vertically fastened to each other. The center of the pivot collar is offset downwardly from the parting plane P.

Body structure of motorcycle

Growing community of inventors

Saitama, Japan

Yoshitaka Seki