| 摘要 |
PURPOSE:To keep a load to an object at a specified value all the time, by comparing signals detected by sensors for the load and displacement of a pressure applying device with preset values, and supplying the specified pressure in correspondence with the signals of excess and shortage. CONSTITUTION:Zero balance of a load cell 3 is obtained by a digital indicator 20. Then desired allowance values of a load is set by an upper- and lower-limit setting device 21. When a shortage signal flows to a specified-pressure holding device 22 from the setting device 21, pressure oil from an oil hydraulic pump 23 flows into a jack 2. When a specified pressure is reached, an oil feeding valve is closed, and a specified load setting is completed. When a horizontal load, which is to be applied to a body under test A, is increased and decreased by an oil jack 6, a load cell 7, and a pressure-oil feeding and discharging pump 8, the fluctuated load is displayed on the indicator 20, signals are sequentially sent to the setting device 21 and the device 22, and the constant load is applied to the body under test A by way of the oil hydraulic pump 23. |
