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EP-4737741-A1 - FLUID PRESSURE CIRCUIT

EP4737741A1EP 4737741 A1EP4737741 A1EP 4737741A1EP-4737741-A1

Abstract

There is provided a fluid pressure circuit that can accumulate fluid having a pressure in a wide range. A fluid pressure circuit includes a driver 1 and a plurality of accumulators 6a and 6b configured to accumulate fluid according to a fluid pressure supplied from the driver 1, and the plurality of accumulators 6a and 6b have different accumulation characteristics.

Inventors

  • ARIKAWA, TATSUHIRO
  • OKAMOTO, YUTA
  • SATO, KOJI
  • SEKI, Tomoki
  • SHIMADA, YOSHIYUKI

Assignees

  • Eagle Industry Co., Ltd.

Dates

Publication Date
20260506
Application Date
20240626

Claims (7)

  1. A fluid pressure circuit, comprising: a driver; and a plurality of accumulators configured to accumulate fluid according to a fluid pressure supplied from the driver, wherein the plurality of accumulators have different accumulation characteristics.
  2. The fluid pressure circuit according to claim 1, further comprising: a switching valve configured to switch a supply destination of the fluid to at least one of the accumulators.
  3. The fluid pressure circuit according to claim 2, wherein the switching valve switches the supply destination to one of the accumulators.
  4. The fluid pressure circuit according to claim 3, wherein a pressure sensor configured to detect the pressure of the fluid is provided between the driver and the accumulators.
  5. The fluid pressure circuit according to claim 1, wherein the driver is a hydraulic cylinder device configured for extending and contracting.
  6. The fluid pressure circuit according to claim 1, wherein a booster is provided between the driver and the accumulators.
  7. The fluid pressure circuit according to any one of claims 1 to 6, further comprising: a regenerative switching valve configured to selectively regenerate the fluid accumulated in the plurality of accumulators.

Description

{TECHNICAL FIELD} The present invention relates to a fluid pressure circuit, and more particularly, to a fluid pressure circuit that includes an accumulator for accumulating working fluid. {BACKGROUND ART} A fluid pressure circuit that utilizes working fluid, such as hydraulic oil, sent out from a fluid supply device, such as a pump, to drive an actuator is known in various fields. In such a fluid pressure circuit, for example, oil discharged from a hydraulic cylinder device as an actuator is accumulated in an accumulator in accordance with the contraction operation of the hydraulic cylinder device and is regenerated during the extension operation of the hydraulic cylinder device. For example, a fluid pressure circuit that increases the pressure of working fluid discharged from a hydraulic cylinder device with a booster and accumulates the working fluid in an accumulator is known (see Patent Citation 1). A fluid pressure circuit illustrated in FIG. 4, which is an example of such a fluid pressure circuit, mainly includes a hydraulic pump 501, a directional control valve 502, a hydraulic cylinder device 503, an electromagnetic switching valve 504, a booster 505, an accumulator 506, and a tank 507. The directional control valve 502 is a spring-centered six-port/three-position type switching valve. In a case where the directional control valve 502 is in a neutral position 502-1, oil discharged from the hydraulic pump 501 is discharged to the tank 507. Further, in a case where the directional control valve 502 is in a left position 502-2, oil discharged from the hydraulic pump 501 is supplied to a first oil chamber 503-1 of the hydraulic cylinder device 503, a part of oil present in a second oil chamber 503-2 of the hydraulic cylinder device 503 is discharged to the tank 507 through an orifice 517, and the other part of the oil flows to the electromagnetic switching valve 504. Accordingly, a workpiece W is moved down. In a case where the directional control valve 502 is in a right position 502-3, a part of oil discharged from the hydraulic pump 501 is supplied to the second oil chamber 503-2 of the hydraulic cylinder device 503 and oil present in the first oil chamber 503-1 of the hydraulic cylinder device 503 is discharged to the tank 507. Accordingly, the workpiece W is moved up. The electromagnetic switching valve 504 is a four-port/two-position type electromagnetic switching valve. The booster 505 includes a case 508 and a piston 509. The case 508 includes a large-diameter tubular portion 508a, a small-diameter tubular portion 508b, and a partition wall portion 508c. The partition wall portion 508c has an annular shape, and partitions the large-diameter tubular portion 508a and the small-diameter tubular portion 508b. The piston 509 includes a large-diameter portion 509a, a small-diameter portion 509b, and a shaft portion 509c, and is enclosed in the case 508 to be slidable in an axial direction. The electromagnetic switching valve 504 is located at a first position 504-1 in a demagnetized state, oil supplied from the hydraulic cylinder device 503 is introduced into an oil chamber 505-1 of the booster 505, and oil present in an oil chamber 505-2 is discharged to the tank 507. Accordingly, the piston 509 is moved to a right side, and oil present in the oil chamber 505-3 is extruded and flows into the accumulator 506 through a check valve 510. At the same time, negative pressure is generated in an oil chamber 505-4 of the booster 505, so that oil present in the tank 507 is sucked into the oil chamber 505-4 through the check valve 511. On the other hand, in a case where the electromagnetic switching valve 504 is switched to a second position 504-2, oil supplied from the hydraulic cylinder device 503 is introduced into the oil chamber 505-2 of the booster 505 and oil present in the oil chamber 505-1 is discharged to the tank 507. Accordingly, the piston 509 is moved to a left side, and oil present in the oil chamber 505-4 is extruded and flows into the accumulator 506 through a check valve 512. At the same time, negative pressure is generated in the oil chamber 505-3 of the booster 505, so that oil present in the tank 507 is sucked into the oil chamber 505-3 through a check valve 513. In a case where the area of a left surface of the large-diameter portion 509a of the piston 509 is denoted by A, the area of a right surface of the large-diameter portion 509a is denoted by B, the area of a right surface of the small-diameter portion 509b is denoted by C, and the area of a left surface of the small-diameter portion 509b is denoted by D, the pressure of oil extruded from the inside of the oil chamber 505-3 in a demagnetized state of the electromagnetic switching valve 504 according to Pascal's principle is increased up to a maximum of A/C times and the oil flows into the accumulator 506. Further, the pressure of oil extruded from the inside of the oil chamber 505-4 in an excited state of the electromagnetic switchin