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Patent Searching and Data


Title:
HYDRAULIC DEVICE
Document Type and Number:
WIPO Patent Application WO/2004/085855
Kind Code:
A1
Abstract:
A hydraulic device capable of performing stable pressing. The device has a hydraulic pump (1) that is driven by an electric motor (6) and can be rotated in both directions. In the device, both ports (14, 16) of a hydraulic cylinder (12) and both ports (2, 4) of the hydraulic pump (1) are individually connected by means of a pair of flow passages (8, 10). With the hydraulic cylinder (12) pressed against a stationary object, a restrictor (32) is provided in a leak flow passage (30) linking a high- pressure side flow passage (10), out of the flow passages (8, 10), to the low-pressure side. Further, the device has a position control circuit (38), a pressure control circuit (40), and a switching circuit (42). The position control circuit (38) controls the electric motor (6) based on a position detected by a movement-detecting sensor (34) for detecting the movement of an object to be transported caused by the hydraulic cylinder (12). The pressure control circuit (40) controls the electric motor (6) based on the pressure, detected by a pressure sensor (36), in the high-pressure side flow passage (10). The switching circuit (42) switches the control by the position control circuit (38) to the pressure control circuit (40).

Inventors:
YOGO TERUAKI (JP)
Application Number:
PCT/JP2004/002657
Publication Date:
October 07, 2004
Filing Date:
March 03, 2004
Export Citation:
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Assignee:
OPTON KK (JP)
YOGO TERUAKI (JP)
International Classes:
F04B49/06; F15B9/09; F15B21/08; (IPC1-7): F15B11/02
Foreign References:
JPH11156412A1999-06-15
JPH10331803A1998-12-15
JPS58102807A1983-06-18
JPS5416634B21979-06-23
JP2000264034A2000-09-26
JPH1026101A1998-01-27
US4041704A1977-08-16
JPH1026101A1998-01-27
Other References:
See also references of EP 1600641A4
Attorney, Agent or Firm:
Adachi, Tsutomu (9-27 Nishiki 2-chome, Naka-k, Nagoya-shi Aichi, JP)
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