Title:
CAPACITY CONTROL DEVICE IN VARIABLE CAPACITY HYDRAULIC PUMP
Document Type and Number:
WIPO Patent Application WO/1994/010447
Kind Code:
A1
Abstract:
A capacity control device in a variable capacity hydraulic pump comprising: a capacity control piston (6) provided with a large diameter chamber (7), for operating a capacity control member (5) of the variable capacity hydraulic pump (1) in a direction of decreasing or increasing the capacity by supplying or discharching pressure oil to or from said large diameter chamber (7); a first control valve (8) and a second control valve (9) for selectively allowing said large diameter chamber of said capacity control piston to communicate with a pump discharge path or a tank; said first control being set to a supply position by the pump discharge pressure and to a drain position by a spring linked with said capacity control piston through a feedback lever, and said second control valve being set to a first position for establishing communication between the pump discharge path and said large diameter chamber by the pump discharge pressure and to a second position for establishing communication between said large diameter chamber and said first control valve by negative pressure; wherein a flow sectional area of an oil path between said large diameter chamber and the pump discharge path or the tank is changed. With this arrangement, a change in the flow sectional area in an intermediate portion of the oil path can change the supply or discharge speed of the pump discharge pressure to the large diameter chamber of said capacity control piston, whereby the responsiveness of the capacity control of said variable hydraulic pump can be regulated, thereby improving the operability of a working machine.
Inventors:
ODA YOSUKE (JP)
SHIRAI KIYOSHI (JP)
SHIRAI KIYOSHI (JP)
Application Number:
PCT/JP1993/001577
Publication Date:
May 11, 1994
Filing Date:
October 29, 1993
Export Citation:
Assignee:
KOMATSU MFG CO LTD (JP)
ODA YOSUKE (JP)
SHIRAI KIYOSHI (JP)
ODA YOSUKE (JP)
SHIRAI KIYOSHI (JP)
International Classes:
F04B49/00; F04B49/08; (IPC1-7): F04B49/00; F04B49/08
Foreign References:
| JPH0462376U | 1992-05-28 | |||
| JPH02286963A | 1990-11-27 | |||
| JPS62191682A | 1987-08-22 | |||
| JPH0462379U | 1992-05-28 | |||
| JPH05172107A | 1993-07-09 |
Other References:
See also references of EP 0667452A4
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