Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Shin Watanabe

Yoshiyuki Kurayoshi

Satoshi Hirayanagi

Hiroaki Tsukui

Takao Mikami

Hisashi Matsuo

Jun Hariu

Yoshitaka Seki

Toshimitsu Suzuki

Takashi Doi

Shin Sato

Mituru Yamamoto

Eiichi Kanda

Koichi Ota

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

A seat rail extending rearwardly from a vehicle body frame to support a seat. The seat rail is formed of a left-and-right two-split cast product having a substantially flat upper surface and, at the same time, includes cross members. These cross members can be mounted later using bolts. The seat can be arranged above the seat rail and the cross members and, at the same time, a seat engaging member which engages the seat with the cross member can be formed on the cross member. The seat rail is constituted of the left and right seat rails which are divided with respect to a vehicle width center. This seat rail structure provides for simple manufacture and assembly.

Seat rail structure

The present invention relates to an improvement in an exhaust system structure for a motorcycle. A motorcycle has an engine disposed between front and rear wheels, an exhaust pipe extending from the engine, and a silencer connected to the exhaust pipe for discharging exhaust gases. The silencer, which is a heavy object, is of the type having a gas outlet disposed near a gas inlet. The silencer is disposed below the engine with the gas inlet facing toward the rear wheel, and the exhaust pipe extends to a position near the rear wheel and is connected to the gas inlet of the silencer. By elongating the length of the exhaust pipe and placing the silencer under the engine, the exhaust system performs sufficiently with high output engines, while at the same time lowers the center of gravity of a motorcycle body and balances the weight of the motorcycle body in its longitudinal direction.

Exhaust system structure for motorcycle

A screen for attachment to an front forked portion of a motorcycle has improved aerodynamic characteristics. An upper garnish is located on the forward side of the screen. The upper garnish extends substantially horizontally across the screen. An expanded portion protrudes forwardly and extends substantially across the entire length of the upper garnish. The expanded portion redirects any horizontal air current impacting thereagainst. The redirected air current influences the horizontal air currents impacting the screen by causing a turbulence area slightly in front of the screen. This turbulence acts to lessen the impact of the horizontal air currents against the screen, resulting in a decrease in an overall running resistance of the motorcycle.

Windshield device in a motorcycle

Growing community of inventors

Saitama, Japan

Shin Watanabe