Pilot operated type relief valve

Abstract

Abstract PURPOSE: To provide a highly responsive relief valve operated by a pilot, wherein between an inlet and a pilot relief valve is arranged a throttle valve having a space which will be varied in response to the pilot flow rate to transmit the generated pressure difference to upper and lower portions of a main piston. CONSTITUTION: When the pressure difference of a flow inlet 5 exceeds a predetermined value of a pilot relief valve 10, a poppet 9 is opened, and a pilot flow will flow will flow from the flow inlet 5 through a space 27 between a circumferential groove 20 and a throttle land 15a, a throttle 25, and poppet 9 and a center of a spring 9 to a flow outlet 6. The pressure difference generated between the front and rear of the throttle 25 is transmitted to chambers 17, 18, while a spool 25 is then pushed to the right to throttle the space 27, and the pressure in the chamber 12 is lowered so that a main piston is elevated to open a space 14 directly communicating the flow inlet 5 with the flow outlet 6. When the inflow pressure increases sharply, the space 27 will be further throttle by the spool 15 to open the space 14 highly responsively, and when the inflow pressured decreases sharply, the reversed action will be promptly taken place. Thus a highly responsive relief valve which will be operated by a pilot is provided. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Akio Mito
• 👤 Yoshisuke Akita
• 👤 Kazuyuki Kihara
• 👤 Shoji Zama

Bibliographic Details