Honda Giken Kogyo Kabushiki Kaisha

Hitoshi Toyoda

Kazumi Miyake

Kagehisa Hamazaki

Yoshikatsu Higuchi

Hiroshi Gomi

Hideaki Takahashi

Jun Ito

Kazushi Hamaya

Yasunobu Kawakami

Yoshinari Takemura

Ken-Ichi Ogawa

Naoki Ota

In a legged mobile robot (), each leg () has at least a first joint () and a second joint () located below the first joint in the gravitational direction, and the actuator that drives the second joint () is located at least one of a position same as that of the first joint and a position () above the first joint in the gravitational direction. With this, it becomes possible to lighten the weight of the ground-contacting ends of the legs and thereby provide a legged mobile robot enabling reduction of the inertial forces occurring in the legs during moving, particularly during high-speed moving.

Legged mobile robot

A silicon nitride reaction-sintered body having a high mechanical strength without surface working can be produced by (1) forming a silicon powder mixture of at least two types of silicon powders having substantially independent particle size distribution ranges into a green body, the silicon powder mixture having an average particle size ranging from 5 .mu.m to 300 .mu.m; (2) heating the green body in a nitrogen-containing atmosphere for nitrogenation; and (3) sintering the nitrogenated green body at a temperature of 1900.degree. C. or higher.

Method for producing silicon nitride reaction sintered body

A composite powder having a specific surface area of 7 m.sup.2 /g or more is produced by mixing a silicon powder with a carbonaceous powder and a sintering aid powder, and heat-treating the resultant mixed powder in a nitrogen-containing atmosphere at a temperature of 1,450.degree. C. or lower thereby nitriding and carbonizing silicon in the mixed powder. The temperature elevation speed in the heat treatment for nitriding and carbonizing is less than 2.degree. C./minute at least in a range from a temperature at which the nitriding and carbonizing of silicon starts to take place to a temperature at which the composite powder is kept for nitriding and carbonizing of silicon. The composite sintered body is produced by sintering such a composite powder at a temperature of 1,600.degree. C. to 2,200.degree. C.

Composite powder and method of manufacturing sintered body therefrom

Robot

A composite sintered body of silicon nitride and silicon carbide is manufactured by sintering a composite powder or green body of silicon nitride and silicon carbide in a nitrogen gas atmosphere. The composite powder having a percentage of .alpha.-silicon nitride which is at least 30% based on all silicon nitride is produced by mixing a silicon powder with a carbonaceous powder and a sintering aid powder, and heat-treating the resultant mixed powder in a nitrogen-containing atmosphere at a temperature of 1,450.degree. C. or lower thereby nitriding and carbonizing silicon contained in the mixed powder to produce a composite powder, a temperature elevation speed being less than 2.degree. C./minute. The composite green body having a percentage of .alpha.-silicon nitride which is at least 30% based on all silicon nitride is produced by mixing a silicon powder, a carbonaceous powder and a sintering aid powder, molding the resultant mixed powder into a green body, and heat-treating the resultant green body in a nitrogen-containing atmosphere at a temperature of 1,450.degree. C. or lower thereby nitriding and carbonizing silicon contained in the green body, a temperature elevation speed being less than 2.degree. C./minute.

Composite powder comprising silicon nitride and silicon carbide

Method for producing silicon nitride reaction-sintered body

A sintered composite body of silicon nitride and silicon carbide is manufactured by mixing a silicon powder with a carbonaceous powder and a sintering additive, producing a mixture, molding the mixture into a molded body, heat-treating the molded body in an atmosphere containing a nitrogen gas for thereby simultaneously nitriding and carbonizing silicon contained in the molded body, and subsequently firing the molded body in a nitrogen gas atmosphere. A composite powder of silicon nitride and silicon carbide which is produced by simultaneously nitriding and carbonizing silicon contained in the molded body has a content of .alpha.-type silicon nitride which is at least 30% of all silicon nitride in the composite powder. To produce such a composite powder, a silicon powder is mixed with a carbonaceous powder and a sintering additive, producing a mixture, and the mixture is heat-treated in an atmosphere containing a nitrogen gas at a temperature of at most 1450.degree. C. for thereby simultaneously nitriding and carbonizing silicon contained in the mixture, the arrangement being such that the temperature of the mixture is increased at a rate lower than 2.degree. C./minute from a temperature before the silicon starts being nitrided and carbonized up to the temperature of at most 1450.degree. C.

Method of manufacturing a sintered composite body of silicon nitride and

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Saitama-ken, Japan

Hitoshi Toyoda