| 摘要 |
<p>PURPOSE:To provide a speed control device for a pig running in a pipe, by which sudden rise of speed due to the dead load at downward running and high speed running generated by sudden acceleration after stop can be restrained. CONSTITUTION:A main body 11 is provided with a cylinder 31 in which the piston 32 is received capably of being reciprocated, both chambers 31A, 31B in the cylinder 31 are connected together with a pipeline 34 having a flow control valve 35 on the way, and a motion transmission and conversion mechanism 41 by which rotation of a wheel 15A is transmitted and converted to the reciprocating motion of the piston 32 is provided. When the wheel is rotated, the piston is reciprocated, hereby at reciprocating fluid of the cylinder in the popeline resistance is generated by the flow control means, and hence high speed reciprocating motion of the piston and high speed rotation of the wheel can be limited, so as to finally restrain excessive high speed running of a pig.</p> |
