| 摘要 |
PURPOSE:To execute a long stroke test and a high-frequency test with the same testing machine by providing a stroke control mechanism which can control the length between end faces of a hydraulic cylinder for the purpose of controlling increase and reduction of the volume of an operating liquid in the hydraulic cylinder. CONSTITUTION:In case of the long stroke test, a switching valve V2 is opened to supply a pressurized liquid to a chamber 14, and a switching valve V3 is opened to discharge the pressurized liquid from a chamber 21. In this case, switching valves V1 and V4 are closed. Then, auxiliary pistons 13 and 13' are moved until they are brought into contact with a bearing block 12, and they are pressed to the bearing block 12 with a force (A1XP1). In this state, the long stroke test with a long stroke (one-side stroke) S1 is executed, and a piston rod 5a is vibrated to test an object 4 to be tested. In case of the high frequency test, the switching valve V1 is opened to supply the pressurized liquid to the chamber, and the switching valve V4 is opened to discharge the pressurized liquid from the chamber 14. In this case, switching valves V2 and V3 are closed. |
