Autonomously navigating vehicle

An autonomously navigating vehicle, equipped with a chassis, a cover, and a suspension mechanism interposed between the chassis and the cover through a lock member at one end, and having at least an attachment shaft attached to the chassis at other end, which vehicle runs on drive wheels attached to the chassis, wherein the suspension mechanism of the autonomously navigating vehicle comprises:

• a tube member that is movably attached to the attachment shaft;
• a first attachment shaft retaining member provided on the chassis to swingably retain the attachment shaft with the tube member;
• a shaft lower end portion provided at lowermost part of the attachment shaft;
• and
• a second attachment shaft retaining member provided on the chassis below the first attachment shaft retaining member to retain the attachment shaft;
• wherein the second attachment shaft retaining member includes a vertex equivalent section and an inner surface defined as a portion of a vertical cross section that passes through the vertex equivalent section is formed in an arc shape,
• the inner surface includes a curve equivalent section continuous with the vertex equivalent section, and
• the second attachment shaft retaining member retains the attachment shaft with the shaft lower end portion abutted onto at least one of the vertex equivalent section and the curve equivalent section.