| 摘要 |
<p>An independent, portable hydraulic unit (80) for powering a hydraulic tool (C), and a method for operating the tool (C) with the aid of the unit. The unit includes a hydraulic circuit (1) having a pump (19), and a power source (17) and a pump motor (18). The pump (19) is intended to pressurize the tool (C) to a first pressure level (P2). The hydraulic circuit includes means (31, P2, X, 12) for charging the hydraulic accumulator (22) to a maximum second pressure level (P1) which is at most equal to the first pressure level (P2). These means include means (31) for isolating the hydraulic accumulator (22) from the pump pressure when this pressure exceeds the second pressure level (P1). First regulating means (12, 21) are provided for enabling the charged accumulator (22) to be connected to the tool upon activation of the unit so as to power the tool, and second regulating means (P2, X, 12) are provided for causing the pump (19) to charge the accumulator to the second pressure level while the tool is relieved of pressure, after emptying the accumulator (22). The power unit (80) is controlled so as to isolate the accumulator (22) from the pump after charging the accumulator to the second pressure level (P1). After emptying the accumulator into the tool, the pump (19) pressurizes the tool (C) to the first pressure level (P2). The accumulator (22) is charged by the pump (19), while the tool (C) is relieved of pressure and isolated from the pump (19).</p> |
