| 摘要 |
PURPOSE:To make it possible not only to suppress the hooking of impurities such as straw present in mud but also to reduce the extrusion amount of mud, by providing a pressure receiving film like body and a pressure sensor to an earth body. CONSTITUTION:A cylindrical case 13 having an opening part formed to the front part thereof in an advance direction is provided to an earth body 12 in a state thrusted in soil and a flexible pressure receiving film body 14 closing said opening part is attached to the front lower end part of the case 13 while the case 13 and a hose 15 are hermetically sealed with a non-compressive fluid such as water. Further, a pressure sensor 16, which converts the change in the pressure acted on the film like body 14 and propagated through the sealed fluid to an electric signal to continuously detect the same as the specific hardness of soil, is provided to the end part of the hose 15 extended in the vicinity of the operation part of a main machine. A pressure sensing chamber 17 opened to the lower part of the earth body 12 is formed to an earth pressure detector S3(S4) and a pressure receiving film like body 18 closing said opening part is attached while the sensing chamber 17 and a hose 19 are sealed with a fluid and, further, a pressure sensor 20 for continuously detecting the change in pressure is provided. |
