Measuring device of crane

Abstract

Abstract PURPOSE: To measure the weight of a hoisting load with high accuracy by a method wherein an operation is performed by a specified relational formula obtained from a weight signal of an empty bucket, two signals of the known weight and an input electric power of a motor when a known weight is hoisted. CONSTITUTION: The input electric power of the motor for the crane is operated in an electric power conversion circuit IN and it is stored as well as a weight signal of an empty bucket and two signals of the known weight, in memories M 1 WM 3 . And by means of these outputs, the previously determined relational formula is operated through the 1st arithmetic circuit CP 1 to obtain an unknown constant, and further, the output is controlled through a comparison circuit DF, and a relational formula containing the unknown constant is operated through the 2nd arithmetic circuit CP 2 . And thereafter, the weight of an empty bucket is subtracted through the 3rd arithmetic circuit CP 3 to display the weight of a load on a display unit DP. As a result, even in a range where a proportional relation between the input power of the motor and the weight of the load is lost, the measurement of high accuracy can be performed. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Toyoji Kaneda
• 👤 Yoshihiko Nakagawa
• 👤 Toshihito Watanabe

Bibliographic Details