Fluid circuit

A fluid circuit, comprising:

• a fluid supply device configured to deliver a working fluid;
• and
• pressure-increasing devices configured to increase a pressure of the working fluid,
• wherein each of the pressure-increasing devices includes a cylinder connected to the fluid supply device, and a piston provided inside the cylinder and configured to be reciprocatable in an axial direction, and delivers, from the cylinder, the working fluid having the pressure which is increased due to a movement of the piston toward a pressure-increasing chamber inside the cylinder by the working fluid delivered from the fluid supply device,
• the pressure-increasing devices are connected in parallel to the fluid supply device,
• wherein the fluid circuit further comprises a pilot switching valve provided for each of the pressure-increasing devices, each of which uses the working fluid delivered from the fluid supply device, as a pilot fluid,
• wherein each of the pilot switching valves has a port and valve positions and is configured to switch between the valve positions according to pressure acting on the port,
• wherein each of the pressure-increasing devices is configured to switch stroke directions of the piston according to the valve position of each of the pilot switching valves,
• and
• wherein the fluid circuit further comprises a adjustable flow return valve which is configured to supply each of pressures having different pressure waves to each of the ports of the pilot switching valves such that a phase of the piston of at least one of the pressure-increasing devices is different from a phase of the piston of remaining at least one of the pressure-increasing devices.