It is an object of the present invention to provide a drive unit for a direct-acting valve for internal combustion engines by which a quiet internal combustion engine can be obtained with noise suppressed. The remaining portion of the solid fuel andor liquid fuel is introduced into a first stage of a multi-stage combustor, resulting in formation of products of combustion and ash andor char. The shell forms a concave portion. The link management will mirror the status of the two links to thereby keep the application platform unobtrusive, i.